Composition for use in the reproduction of line documents



Patented ca. 30, 1924.

UNITED STATES JEAN DOREL, 0F NICE, FRANCE.

COMPOSITION FOR USE IN THE REPRODUCTIONDF LINE DOCUMENTS.

No Drawing.

To all whom it may concern:

Be it known that I, JEAN DOREL, a citizen of the French Republic, and residing in Nice, Alpes Maritimes, France, have invented certain new and useful Improvements in and Relating to Composition for Use in the Reproduction of Line-Documents, of which the following is a complete specification.

This invention relates to a method of preparing gelatinous chemical compositions unaffected by air or light used for the copying of tracings of all kinds, and of strengthening printing blocks obtained'with these compositions, and is more particularly applicable to thecopying of tracings of all kinds, such as, line drawings, in ink or in pencil, writings, music and others, according to the ferrogelatinographic method.

The ferrogelatinographic methodis carried outas follows:

The gelatinous chemical composition is spread hot on a sheet of zinc or other metal. When this composition has taken, and has quite hardened, a photographic paper, called ferro-prussiate paper (blue) is placed on it, in the dry state, without being allowed to remain, care being taken to previously expose the paper behind the tracing to be copied. The application of the blue print being terminated, a roller covered with rich ink, (for example printing ink) is passed over the gelatinous composition, and, when all the lines of the printing block are filled, the drawing ofi of copies is proceeded with. The present gelatinous compositions havethe disadvantage of'onlv allowing a limited number of copies to be drawn ofi', whilst, on the other hand, they alter with time and lose their properties, due to the presence in their composition of ferrous sulphate which is oxidized by contact with the air.

The method according to the invention, which obviates these disadvantages, consists inincorporating in the gelatine which con-- stitutes the base of the printing block a substance which is not attacked by theoxygen in the air or h light, and which has no action on the ge atine, but which will forma precipitate or an im ermeable combination with the sensitive su stance, kept sheltered from exposure. a

For making up the gelatinous compositions the ferrous sulphate, which is used in usualgelatinous compositions, is re- Application filed September 24, 1824. Serial No. 789,682.

placed by a substance which is inert with regard to the gelatine.

As examples of substances which fulfil these conditions certain sulphates may be" named, and more particularly the sulphates of nickel, of zinc, of manganese, of cobalt, of copper or others. These sulphates which I designate sulphatesv of the nickel-cobaltcopper-zincmanganese sulphate type are practically unafl'ected'by the action of light and of the oxygen in the air, and have no action on gelatine, and they also possess the property of forming with the prussiate (either yellow prussiate or ferro-cyanide of. potassium, or red prussiate or ferricyanide of potassium) which enters into the composition of the sensitized paper used in the ferrogelatinographic method. a precipitate of great strength, to resist both the mechanical action of inking and the action of the. moisture contained, in the gelatine, which enablesclear lines and a great number of copies to be obtained. K

On the other hand, to enable perfect copies to be obtained it is preferable to colour the surface of the gelatine, which has to constitute the printing block, making the colour as near white as possible, so that the operator will more easily see possible faults in the printing block. A white colouration of this printing block will be obtained .by embodying in the gelatinous composition a substance such as zinc oxide (zinc white) or an analogous substance, in suitable proportions. a

The gelatinous composition may thus consist of the following substances in the proportions given:

Gelatine 1 kilo. Water 4 litres. Nickel sulphate 100 grams. Light of oxide of zinc- 150 Glycerine 150 cmc.

The preparation of the gelatinous composition intended to be used for making the printing block, is proceeded with in the usual manner, and this paste for the preparation of the printing block will also be utilized in the usual manner. When, in order to prepare the printing block, the sheet of ferro-prussiate paper, which has been suitably exposedlbehind the copy or tracing. to be reproduced, is placed on the surface of the gelatine, suitably laid out, theparts of the ferro-prussiate which have not been attacked by the light, form with the nickel sulphate, in combination with the gelatine, an im ermeable precipitate of great strength, through which the moisture of the gelatine cannot pass, and which lasts for-a very long time, in spite of the repeated backward and forward movement of the inking roller. This composition enables a number of copies to be drawn off the printing block, which number nickel sulphate will be used for the sulphates mentioned above, exception being made however in the case of copper sulphate, of which it will be suflicient to mix grams instead of 150 grams. in the gelatinous composition to obtain the desired result.

Owing to the presence of zinc oxide, or

.zinc white, in the composition, the printing block is white in colour, and tends to even brighten in colour in contact with the air, which greatly facilitates the obtaining of prints or copies without faults.

The zinc oxide may be replaced by analogous substances such as for example, bismuth oxy-chloride, bismuth carbonate, or bismuth sub-nitrate. These substances may also be replaced by calcined aluminium, whitening, or analogous substances, of suitable density.

A mixture in suitable proportions of the different sulphates mentioned above or of the analogous substances may be introduced into the gelatinous composition. These mixtures may be used in any. suitable proportions, which proportions may be decided for each particular case. Similarly the colouration of the gelatinous composition may be obtained by embodying only one of the substances mentioned above or a mixture of these substances.

Instead of embodying the substances mentioned above in the gelatinous composition during its manufacture, any one of the given sulphates may be applied to the surface alone of the gelatine, suitably laid out for this purpose, thus I ivin tine surface possessing a l the properties of the gelatinous compositions mentioned above.

For this purpose, the gelatine which has preferably been previously coloured white, having been spread out by melting and subinstantly a gela- I sequent cooling, the chosen sulphate is ap lied to the surface of this elatine in the ollowing manner: a solutlon of nickel sulphate in water comprising for example 25 grams of nickel sulphate to one litre of water, is spread uniformly on pa er by any desired method. This paper is dried, then a piece the size of the printing block which it is proposed to prepare is cut out and its whitened side is applied on the gelatinous composition before the application of the blue print. A stron' printing block may thus be obtained ena ling a hundred or so copies to be drawn off.

Any one of the sulphates mentioned above may be used for preparing the solution,

the proportion being25 grams of sulphate This method may also be applied to the 1 strengthening of printing blocks made by the use of any'gelatinous composition so as to increase the output. The desired result may also be obtained by using. instead of a solution of nickel or other sul hate, a solution of ferrous sulphate in t e same proportions which, on a gelatinous composition with a ferrous sulphate base would revive the ferrous sulphate affected by contact with the oxygen in the air.

The invention refers to the preparation of printing blocks for the copying of all tracings, and the substances hereinbefore mentioned may be varied with the nature of the sensitized material which has to be exposed.

What I claim is:

1. A composition for use in the reproduction of line documents comprising gelatin, water, glycerin, light oxide of zinc, and a sulphate of the nickel-cobalt-copper-zincmanganese sulphate type, which is unaffected by the oxygen of the air.

2. A composition for use in the reproduction of line documents comprising gelatin, water, glycerin, light oxide of zinc, and nickel sulphate. g

3., A composition for use in the reproduction of line documents comprising gelatin, 1 kilo; water 4 liters; nickel sulphate, 100

grams; light oxide of zinc, 150 grams; and

DOREL. 

